SI-H Muscle Testers
14
WORLD PRECISION IN STRU MENTS
Fig. 15 The Linear Motor is an optional part for the SI-MT or SI-MKB systems.
The position of the linear motor is determined by a combination of the data from the
controller indicating the current position and the DC value applied to the front panel at
the Position In port. The applied Position In signal can be provided by a data acquisition
system. The data acquisition analog output signal is set to defi ne the waveform and
timing pattern of force to be applied to the sample.
The Linear Motor Controller has been designed with an automatic shutoff feature. That
means that the voltage driving the motor automatically shuts off if the motor draws too
much current. After less than a second, the motor cycles back on again. If the setup still
draws too much current, it repeats the power down cycle. This could happen if too much
force is being applied to the sample. The system continues to cycle the motor off and on
until the force on the motor is reduced. If this happens, the motor hums as if it is trying
to work, but the motor produces no force output. If an auto-shutdown occurs, adjust the
experiment and force tension on the motor.
NOTE
: Use of a linear motor with a muscle testing platform creates vibration which
excites the sensor's resonant frequency and requires an anti-oscillation unit (
SI-AOSUB
)
for best results.
This linear motor control unit is only available as a module for the Signal Conditioning
Amplifi er System backplane.
Features
The
SI-MOTDB
Linear Motor Controller has the following features:
•
Powers the motor and provides an output indicating the actual motor position
•
Connects to Analog to Digital Converter output of the computer or data acquisition
system (like LabTrax 8/16) to allow the programming to control the waveform and
timing of the motor control
•
Input range of ±10VDC
•
Over current protection that automatically shuts down when the supply voltage dips
below the reference value
•
Linear motor position is determined by a DC value applied from the Position In port
